Effect of Hz and TNF-α added at different concentrations on erythroid expansion and phenotype in erythroid cultures. (A) Cell expansion was measured at day 11. The bars represent mean inhibition of erythroid expansion compared with control wells containing medium (dotted bar). The error bars show the SEM of 3 independent experiments. ^*P < .05; ^**P < .01. (B) Cells were stained with CD71-PE and GpA-FITC and analyzed by flow cytometry. These plots correspond to a representative experiment.